Just another person requesting Undo feature and displaying Clues first when puzzle is loaded. For Undo, a button that Saves the current state of the puzzle would be required - Undo would then go to Saved state. Player would be required to Save the puzzle as needed. If player has not saved the puzzle, Undo would function the same as clearing the grid to start over. Hope this makes sense and I HOPE these enhancements can be made to an otherwise excellent site.